How to Install OpenJDK 7 on Ubuntu 13.04, 12.10 and 12.04

In this article I will show you how to install OpenJDK 7 on Ubuntu 13.04 Raring Ringtail, Ubuntu 12.10 Quantal Quetzal and Ubuntu 12.04 Precise Pangolin. If you do not like Oracle Java (Oracle JDK) you can install this one.